// TODO actually recognize syntax of TypeScript constructs

CodeMirror.defineMode("javascript", function (config, parserConfig) {
    var indentUnit = config.indentUnit;
    var statementIndent = parserConfig.statementIndent;
    var jsonMode = parserConfig.json;
    var isTS = parserConfig.typescript;

    // Tokenizer

    var keywords = function () {
        function kw(type) {
            return {type: type, style: "keyword"};
        }

        var A = kw("keyword a"), B = kw("keyword b"), C = kw("keyword c");
        var operator = kw("operator"), atom = {type: "atom", style: "atom"};

        var jsKeywords = {
            "if": kw("if"), "while": A, "with": A, "else": B, "do": B, "try": B, "finally": B,
            "return": C, "break": C, "continue": C, "new": C, "delete": C, "throw": C,
            "var": kw("var"), "const": kw("var"), "let": kw("var"),
            "function": kw("function"), "catch": kw("catch"),
            "for": kw("for"), "switch": kw("switch"), "case": kw("case"), "default": kw("default"),
            "in": operator, "typeof": operator, "instanceof": operator,
            "true": atom, "false": atom, "null": atom, "undefined": atom, "NaN": atom, "Infinity": atom,
            "this": kw("this"), "module": kw("module"), "class": kw("class"), "super": kw("atom"),
            "yield": C, "export": kw("export"), "import": kw("import"), "extends": C
        };

        // Extend the 'normal' keywords with the TypeScript language extensions
        if (isTS) {
            var type = {type: "variable", style: "variable-3"};
            var tsKeywords = {
                // object-like things
                "interface": kw("interface"),
                "extends": kw("extends"),
                "constructor": kw("constructor"),

                // scope modifiers
                "public": kw("public"),
                "private": kw("private"),
                "protected": kw("protected"),
                "static": kw("static"),

                // types
                "string": type, "number": type, "bool": type, "any": type
            };

            for (var attr in tsKeywords) {
                jsKeywords[attr] = tsKeywords[attr];
            }
        }

        return jsKeywords;
    }();

    var isOperatorChar = /[+\-*&%=<>!?|~^]/;

    function nextUntilUnescaped(stream, end) {
        var escaped = false, next;
        while ((next = stream.next()) != null) {
            if (next == end && !escaped)
                return false;
            escaped = !escaped && next == "\\";
        }
        return escaped;
    }

    // Used as scratch variables to communicate multiple values without
    // consing up tons of objects.
    var type, content;

    function ret(tp, style, cont) {
        type = tp;
        content = cont;
        return style;
    }

    function tokenBase(stream, state) {
        var ch = stream.next();
        if (ch == '"' || ch == "'") {
            state.tokenize = tokenString(ch);
            return state.tokenize(stream, state);
        } else if (ch == "." && stream.match(/^\d+(?:[eE][+\-]?\d+)?/)) {
            return ret("number", "number");
        } else if (ch == "." && stream.match("..")) {
            return ret("spread", "meta");
        } else if (/[\[\]{}\(\),;\:\.]/.test(ch)) {
            return ret(ch);
        } else if (ch == "=" && stream.eat(">")) {
            return ret("=>");
        } else if (ch == "0" && stream.eat(/x/i)) {
            stream.eatWhile(/[\da-f]/i);
            return ret("number", "number");
        } else if (/\d/.test(ch)) {
            stream.match(/^\d*(?:\.\d*)?(?:[eE][+\-]?\d+)?/);
            return ret("number", "number");
        } else if (ch == "/") {
            if (stream.eat("*")) {
                state.tokenize = tokenComment;
                return tokenComment(stream, state);
            } else if (stream.eat("/")) {
                stream.skipToEnd();
                return ret("comment", "comment");
            } else if (state.lastType == "operator" || state.lastType == "keyword c" ||
                state.lastType == "sof" || /^[\[{}\(,;:]$/.test(state.lastType)) {
                nextUntilUnescaped(stream, "/");
                stream.eatWhile(/[gimy]/); // 'y' is "sticky" option in Mozilla
                return ret("regexp", "string-2");
            } else {
                stream.eatWhile(isOperatorChar);
                return ret("operator", null, stream.current());
            }
        } else if (ch == "`") {
            state.tokenize = tokenQuasi;
            return tokenQuasi(stream, state);
        } else if (ch == "#") {
            stream.skipToEnd();
            return ret("error", "error");
        } else if (isOperatorChar.test(ch)) {
            stream.eatWhile(isOperatorChar);
            return ret("operator", null, stream.current());
        } else {
            stream.eatWhile(/[\w\$_]/);
            var word = stream.current(), known = keywords.propertyIsEnumerable(word) && keywords[word];
            return (known && state.lastType != ".") ? ret(known.type, known.style, word) :
                ret("variable", "variable", word);
        }
    }

    function tokenString(quote) {
        return function (stream, state) {
            if (!nextUntilUnescaped(stream, quote))
                state.tokenize = tokenBase;
            return ret("string", "string");
        };
    }

    function tokenComment(stream, state) {
        var maybeEnd = false, ch;
        while (ch = stream.next()) {
            if (ch == "/" && maybeEnd) {
                state.tokenize = tokenBase;
                break;
            }
            maybeEnd = (ch == "*");
        }
        return ret("comment", "comment");
    }

    function tokenQuasi(stream, state) {
        var escaped = false, next;
        while ((next = stream.next()) != null) {
            if (!escaped && (next == "`" || next == "$" && stream.eat("{"))) {
                state.tokenize = tokenBase;
                break;
            }
            escaped = !escaped && next == "\\";
        }
        return ret("quasi", "string-2", stream.current());
    }

    var brackets = "([{}])";
    // This is a crude lookahead trick to try and notice that we're
    // parsing the argument patterns for a fat-arrow function before we
    // actually hit the arrow token. It only works if the arrow is on
    // the same line as the arguments and there's no strange noise
    // (comments) in between. Fallback is to only notice when we hit the
    // arrow, and not declare the arguments as locals for the arrow
    // body.
    function findFatArrow(stream, state) {
        if (state.fatArrowAt) state.fatArrowAt = null;
        var arrow = stream.string.indexOf("=>", stream.start);
        if (arrow < 0) return;

        var depth = 0, sawSomething = false;
        for (var pos = arrow - 1; pos >= 0; --pos) {
            var ch = stream.string.charAt(pos);
            var bracket = brackets.indexOf(ch);
            if (bracket >= 0 && bracket < 3) {
                if (!depth) {
                    ++pos;
                    break;
                }
                if (--depth == 0) break;
            } else if (bracket >= 3 && bracket < 6) {
                ++depth;
            } else if (/[$\w]/.test(ch)) {
                sawSomething = true;
            } else if (sawSomething && !depth) {
                ++pos;
                break;
            }
        }
        if (sawSomething && !depth) state.fatArrowAt = pos;
    }

    // Parser

    var atomicTypes = {"atom": true, "number": true, "variable": true, "string": true, "regexp": true, "this": true};

    function JSLexical(indented, column, type, align, prev, info) {
        this.indented = indented;
        this.column = column;
        this.type = type;
        this.prev = prev;
        this.info = info;
        if (align != null) this.align = align;
    }

    function inScope(state, varname) {
        for (var v = state.localVars; v; v = v.next)
            if (v.name == varname) return true;
        for (var cx = state.context; cx; cx = cx.prev) {
            for (var v = cx.vars; v; v = v.next)
                if (v.name == varname) return true;
        }
    }

    function parseJS(state, style, type, content, stream) {
        var cc = state.cc;
        // Communicate our context to the combinators.
        // (Less wasteful than consing up a hundred closures on every call.)
        cx.state = state;
        cx.stream = stream;
        cx.marked = null, cx.cc = cc;

        if (!state.lexical.hasOwnProperty("align"))
            state.lexical.align = true;

        while (true) {
            var combinator = cc.length ? cc.pop() : jsonMode ? expression : statement;
            if (combinator(type, content)) {
                while (cc.length && cc[cc.length - 1].lex)
                    cc.pop()();
                if (cx.marked) return cx.marked;
                if (type == "variable" && inScope(state, content)) return "variable-2";
                return style;
            }
        }
    }

    // Combinator utils

    var cx = {state: null, column: null, marked: null, cc: null};

    function pass() {
        for (var i = arguments.length - 1; i >= 0; i--) cx.cc.push(arguments[i]);
    }

    function cont() {
        pass.apply(null, arguments);
        return true;
    }

    function register(varname) {
        function inList(list) {
            for (var v = list; v; v = v.next)
                if (v.name == varname) return true;
            return false;
        }

        var state = cx.state;
        if (state.context) {
            cx.marked = "def";
            if (inList(state.localVars)) return;
            state.localVars = {name: varname, next: state.localVars};
        } else {
            if (inList(state.globalVars)) return;
            if (parserConfig.globalVars)
                state.globalVars = {name: varname, next: state.globalVars};
        }
    }

    // Combinators

    var defaultVars = {name: "this", next: {name: "arguments"}};

    function pushcontext() {
        cx.state.context = {prev: cx.state.context, vars: cx.state.localVars};
        cx.state.localVars = defaultVars;
    }

    function popcontext() {
        cx.state.localVars = cx.state.context.vars;
        cx.state.context = cx.state.context.prev;
    }

    function pushlex(type, info) {
        var result = function () {
            var state = cx.state, indent = state.indented;
            if (state.lexical.type == "stat") indent = state.lexical.indented;
            state.lexical = new JSLexical(indent, cx.stream.column(), type, null, state.lexical, info);
        };
        result.lex = true;
        return result;
    }

    function poplex() {
        var state = cx.state;
        if (state.lexical.prev) {
            if (state.lexical.type == ")")
                state.indented = state.lexical.indented;
            state.lexical = state.lexical.prev;
        }
    }

    poplex.lex = true;

    function expect(wanted) {
        return function (type) {
            if (type == wanted) return cont();
            else if (wanted == ";") return pass();
            else return cont(arguments.callee);
        };
    }

    function statement(type, value) {
        if (type == "var") return cont(pushlex("vardef", value.length), vardef, expect(";"), poplex);
        if (type == "keyword a") return cont(pushlex("form"), expression, statement, poplex);
        if (type == "keyword b") return cont(pushlex("form"), statement, poplex);
        if (type == "{") return cont(pushlex("}"), block, poplex);
        if (type == ";") return cont();
        if (type == "if") return cont(pushlex("form"), expression, statement, poplex, maybeelse);
        if (type == "function") return cont(functiondef);
        if (type == "for") return cont(pushlex("form"), forspec, poplex, statement, poplex);
        if (type == "variable") return cont(pushlex("stat"), maybelabel);
        if (type == "switch") return cont(pushlex("form"), expression, pushlex("}", "switch"), expect("{"),
            block, poplex, poplex);
        if (type == "case") return cont(expression, expect(":"));
        if (type == "default") return cont(expect(":"));
        if (type == "catch") return cont(pushlex("form"), pushcontext, expect("("), funarg, expect(")"),
            statement, poplex, popcontext);
        if (type == "module") return cont(pushlex("form"), pushcontext, afterModule, popcontext, poplex);
        if (type == "class") return cont(pushlex("form"), className, objlit, poplex);
        if (type == "export") return cont(pushlex("form"), afterExport, poplex);
        if (type == "import") return cont(pushlex("form"), afterImport, poplex);
        return pass(pushlex("stat"), expression, expect(";"), poplex);
    }

    function expression(type) {
        return expressionInner(type, false);
    }

    function expressionNoComma(type) {
        return expressionInner(type, true);
    }

    function expressionInner(type, noComma) {
        if (cx.state.fatArrowAt == cx.stream.start) {
            var body = noComma ? arrowBodyNoComma : arrowBody;
            if (type == "(") return cont(pushcontext, commasep(pattern, ")"), expect("=>"), body, popcontext);
            else if (type == "variable") return pass(pushcontext, pattern, expect("=>"), body, popcontext);
        }

        var maybeop = noComma ? maybeoperatorNoComma : maybeoperatorComma;
        if (atomicTypes.hasOwnProperty(type)) return cont(maybeop);
        if (type == "function") return cont(functiondef);
        if (type == "keyword c") return cont(noComma ? maybeexpressionNoComma : maybeexpression);
        if (type == "(") return cont(pushlex(")"), maybeexpression, comprehension, expect(")"), poplex, maybeop);
        if (type == "operator" || type == "spread") return cont(noComma ? expressionNoComma : expression);
        if (type == "[") return cont(pushlex("]"), expressionNoComma, maybeArrayComprehension, poplex, maybeop);
        if (type == "{") return cont(commasep(objprop, "}"), maybeop);
        return cont();
    }

    function maybeexpression(type) {
        if (type.match(/[;\}\)\],]/)) return pass();
        return pass(expression);
    }

    function maybeexpressionNoComma(type) {
        if (type.match(/[;\}\)\],]/)) return pass();
        return pass(expressionNoComma);
    }

    function maybeoperatorComma(type, value) {
        if (type == ",") return cont(expression);
        return maybeoperatorNoComma(type, value, false);
    }

    function maybeoperatorNoComma(type, value, noComma) {
        var me = noComma == false ? maybeoperatorComma : maybeoperatorNoComma;
        var expr = noComma == false ? expression : expressionNoComma;
        if (value == "=>") return cont(pushcontext, noComma ? arrowBodyNoComma : arrowBody, popcontext);
        if (type == "operator") {
            if (/\+\+|--/.test(value)) return cont(me);
            if (value == "?") return cont(expression, expect(":"), expr);
            return cont(expr);
        }
        if (type == "quasi") {
            cx.cc.push(me);
            return quasi(value);
        }
        if (type == ";") return;
        if (type == "(") return cont(commasep(expressionNoComma, ")", "call"), me);
        if (type == ".") return cont(property, me);
        if (type == "[") return cont(pushlex("]"), maybeexpression, expect("]"), poplex, me);
    }

    function quasi(value) {
        if (!value) debugger;
        if (value.slice(value.length - 2) != "${") return cont();
        return cont(expression, continueQuasi);
    }

    function continueQuasi(type) {
        if (type == "}") {
            cx.marked = "string-2";
            cx.state.tokenize = tokenQuasi;
            return cont();
        }
    }

    function arrowBody(type) {
        findFatArrow(cx.stream, cx.state);
        if (type == "{") return pass(statement);
        return pass(expression);
    }

    function arrowBodyNoComma(type) {
        findFatArrow(cx.stream, cx.state);
        if (type == "{") return pass(statement);
        return pass(expressionNoComma);
    }

    function maybelabel(type) {
        if (type == ":") return cont(poplex, statement);
        return pass(maybeoperatorComma, expect(";"), poplex);
    }

    function property(type) {
        if (type == "variable") {
            cx.marked = "property";
            return cont();
        }
    }

    function objprop(type, value) {
        if (type == "variable") {
            cx.marked = "property";
            if (value == "get" || value == "set") return cont(getterSetter);
        } else if (type == "number" || type == "string") {
            cx.marked = type + " property";
        } else if (type == "[") {
            return cont(expression, expect("]"), afterprop);
        }
        if (atomicTypes.hasOwnProperty(type)) return cont(afterprop);
    }

    function getterSetter(type) {
        if (type != "variable") return pass(afterprop);
        cx.marked = "property";
        return cont(functiondef);
    }

    function afterprop(type) {
        if (type == ":") return cont(expressionNoComma);
        if (type == "(") return pass(functiondef);
    }

    function commasep(what, end, info) {
        function proceed(type) {
            if (type == ",") {
                var lex = cx.state.lexical;
                if (lex.info == "call") lex.pos = (lex.pos || 0) + 1;
                return cont(what, proceed);
            }
            if (type == end) return cont();
            return cont(expect(end));
        }

        return function (type) {
            if (type == end) return cont();
            if (info === false) return pass(what, proceed);
            return pass(pushlex(end, info), what, proceed, poplex);
        };
    }

    function block(type) {
        if (type == "}") return cont();
        return pass(statement, block);
    }

    function maybetype(type) {
        if (isTS && type == ":") return cont(typedef);
    }

    function typedef(type) {
        if (type == "variable") {
            cx.marked = "variable-3";
            return cont();
        }
    }

    function vardef() {
        return pass(pattern, maybetype, maybeAssign, vardefCont);
    }

    function pattern(type, value) {
        if (type == "variable") {
            register(value);
            return cont();
        }
        if (type == "[") return cont(commasep(pattern, "]"));
        if (type == "{") return cont(commasep(proppattern, "}"));
    }

    function proppattern(type, value) {
        if (type == "variable" && !cx.stream.match(/^\s*:/, false)) {
            register(value);
            return cont(maybeAssign);
        }
        if (type == "variable") cx.marked = "property";
        return cont(expect(":"), pattern, maybeAssign);
    }

    function maybeAssign(_type, value) {
        if (value == "=") return cont(expressionNoComma);
    }

    function vardefCont(type) {
        if (type == ",") return cont(vardef);
    }

    function maybeelse(type, value) {
        if (type == "keyword b" && value == "else") return cont(pushlex("form"), statement, poplex);
    }

    function forspec(type) {
        if (type == "(") return cont(pushlex(")"), forspec1, expect(")"));
    }

    function forspec1(type) {
        if (type == "var") return cont(vardef, expect(";"), forspec2);
        if (type == ";") return cont(forspec2);
        if (type == "variable") return cont(formaybeinof);
        return pass(expression, expect(";"), forspec2);
    }

    function formaybeinof(_type, value) {
        if (value == "in" || value == "of") {
            cx.marked = "keyword";
            return cont(expression);
        }
        return cont(maybeoperatorComma, forspec2);
    }

    function forspec2(type, value) {
        if (type == ";") return cont(forspec3);
        if (value == "in" || value == "of") {
            cx.marked = "keyword";
            return cont(expression);
        }
        return pass(expression, expect(";"), forspec3);
    }

    function forspec3(type) {
        if (type != ")") cont(expression);
    }

    function functiondef(type, value) {
        if (value == "*") {
            cx.marked = "keyword";
            return cont(functiondef);
        }
        if (type == "variable") {
            register(value);
            return cont(functiondef);
        }
        if (type == "(") return cont(pushcontext, commasep(funarg, ")"), statement, popcontext);
    }

    function funarg(type) {
        if (type == "spread") return cont(funarg);
        return pass(pattern, maybetype);
    }

    function className(type, value) {
        if (type == "variable") {
            register(value);
            return cont(classNameAfter);
        }
    }

    function classNameAfter(_type, value) {
        if (value == "extends") return cont(expression);
    }

    function objlit(type) {
        if (type == "{") return cont(commasep(objprop, "}"));
    }

    function afterModule(type, value) {
        if (type == "string") return cont(statement);
        if (type == "variable") {
            register(value);
            return cont(maybeFrom);
        }
    }

    function afterExport(_type, value) {
        if (value == "*") {
            cx.marked = "keyword";
            return cont(maybeFrom, expect(";"));
        }
        if (value == "default") {
            cx.marked = "keyword";
            return cont(expression, expect(";"));
        }
        return pass(statement);
    }

    function afterImport(type) {
        if (type == "string") return cont();
        return pass(importSpec, maybeFrom);
    }

    function importSpec(type, value) {
        if (type == "{") return cont(commasep(importSpec, "}"));
        if (type == "variable") register(value);
        return cont();
    }

    function maybeFrom(_type, value) {
        if (value == "from") {
            cx.marked = "keyword";
            return cont(expression);
        }
    }

    function maybeArrayComprehension(type) {
        if (type == "for") return pass(comprehension);
        if (type == ",") return cont(commasep(expressionNoComma, "]", false));
        return pass(commasep(expressionNoComma, "]", false));
    }

    function comprehension(type) {
        if (type == "for") return cont(forspec, comprehension);
        if (type == "if") return cont(expression, comprehension);
    }

    // Interface

    return {
        startState: function (basecolumn) {
            var state = {
                tokenize: tokenBase,
                lastType: "sof",
                cc: [],
                lexical: new JSLexical((basecolumn || 0) - indentUnit, 0, "block", false),
                localVars: parserConfig.localVars,
                context: parserConfig.localVars && {vars: parserConfig.localVars},
                indented: 0
            };
            if (parserConfig.globalVars) state.globalVars = parserConfig.globalVars;
            return state;
        },

        token: function (stream, state) {
            if (stream.sol()) {
                if (!state.lexical.hasOwnProperty("align"))
                    state.lexical.align = false;
                state.indented = stream.indentation();
                findFatArrow(stream, state);
            }
            if (state.tokenize != tokenComment && stream.eatSpace()) return null;
            var style = state.tokenize(stream, state);
            if (type == "comment") return style;
            state.lastType = type == "operator" && (content == "++" || content == "--") ? "incdec" : type;
            return parseJS(state, style, type, content, stream);
        },

        indent: function (state, textAfter) {
            if (state.tokenize == tokenComment) return CodeMirror.Pass;
            if (state.tokenize != tokenBase) return 0;
            var firstChar = textAfter && textAfter.charAt(0), lexical = state.lexical;
            // Kludge to prevent 'maybelse' from blocking lexical scope pops
            for (var i = state.cc.length - 1; i >= 0; --i) {
                var c = state.cc[i];
                if (c == poplex) lexical = lexical.prev;
                else if (c != maybeelse) break;
            }
            if (lexical.type == "stat" && firstChar == "}") lexical = lexical.prev;
            if (statementIndent && lexical.type == ")" && lexical.prev.type == "stat")
                lexical = lexical.prev;
            var type = lexical.type, closing = firstChar == type;

            if (type == "vardef") return lexical.indented + (state.lastType == "operator" || state.lastType == "," ? lexical.info + 1 : 0);
            else if (type == "form" && firstChar == "{") return lexical.indented;
            else if (type == "form") return lexical.indented + indentUnit;
            else if (type == "stat")
                return lexical.indented + (state.lastType == "operator" || state.lastType == "," ? statementIndent || indentUnit : 0);
            else if (lexical.info == "switch" && !closing && parserConfig.doubleIndentSwitch != false)
                return lexical.indented + (/^(?:case|default)\b/.test(textAfter) ? indentUnit : 2 * indentUnit);
            else if (lexical.align) return lexical.column + (closing ? 0 : 1);
            else return lexical.indented + (closing ? 0 : indentUnit);
        },

        electricChars: ":{}",
        blockCommentStart: jsonMode ? null : "/*",
        blockCommentEnd: jsonMode ? null : "*/",
        lineComment: jsonMode ? null : "//",
        fold: "brace",

        helperType: jsonMode ? "json" : "javascript",
        jsonMode: jsonMode
    };
});

CodeMirror.defineMIME("text/javascript", "javascript");
CodeMirror.defineMIME("text/ecmascript", "javascript");
CodeMirror.defineMIME("application/javascript", "javascript");
CodeMirror.defineMIME("application/ecmascript", "javascript");
CodeMirror.defineMIME("application/json", {name: "javascript", json: true});
CodeMirror.defineMIME("application/x-json", {name: "javascript", json: true});
CodeMirror.defineMIME("text/typescript", {name: "javascript", typescript: true});
CodeMirror.defineMIME("application/typescript", {name: "javascript", typescript: true});
